Climate and monthly weather forecast
Sveti Vlas, Bulgaria

Sveti Vlas, Bulgaria, lies within the Humid subtropical climate zone as per the Köppen climate classification - it is described as having a no-dry season climatic variant, denoted as Cfa. The town's climate features significant rainfall throughout the year, including the warmest months. Understanding this climatic classification provides a baseline for the town's monthly weather tendencies and yearly variations.

Monthly average high temperatures show a steady ascension from 5°C (41°F) in January to a summertime peak of 27°C (80.6°F) during July. Conversely, the annual trend for low temperatures begins at around -2°C (28.4°F) in the coldest month of January and warms progressively to reach 17°C (62.6°F) in the month of July. From the warmest to the coldest months, the sea temperature in the vicinity of Sveti Vlas fluctuates between 24.9°C (76.8°F) and 7.4°C (45.3°F).

As for precipitation levels, the yearly pattern reveals an average monthly rainfall ranging from 34mm (1.34") in August to 65mm (2.56") in November. Remarkably, the wettest months also coincide with some of the chilliest periods of the year. In terms of daylight hours, the figure varies from a yearly low of 9.1 hours in December to reach a peak of 15.3 hours during June. Moreover, the average monthly sunshine hours swell from 2 hours in December, the shortest day period, to an expansive 10 hours in July.

The UV index oscillates throughout the year, with a minimum of 1 occurring during the winter months of December and January, to a maximum of 9 during the summer month of July.

Travelers aiming for pleasant warmth and abundant sunshine should consider visiting Sveti Vlas from June to August. During this period, daytime temperatures reach an average peak of 24°C (75.2°F) to 27°C (80.6°F). Correspondingly, the sea temperature attains its maximum value of 24.6°C (76.3°F) to 24.9°C (76.8°F), inviting for various water activities. Moreover, these months showcase a generous amount of sunshine, offering 9 to 10 hours daily, along with long daylight durations fluctuating around 14.6 hours to 15.3 hours.

The least ideal time to visit Sveti Vlas is during the cold winter months of December, January, and February. During these months, average high temperatures plummet as low as 5°C (41°F) to 6°C (42.8°F) and can drop below freezing point at night. Besides, daylight hours are at their minimum, oscillating between 9.1 hours to 10.6 hours. Furthermore, the UV index stands at its annual lowest point indicating a lack of considerable sun strength.

In Sveti Vlas, spring unfolds with an upward trend in temperatures, where average highs rise from 9°C (48.2°F) in March to 20°C (68°F) by May. Correspondingly, monthly low temperatures range between 2°C (35.6°F) and 11°C (51.8°F). During this season, sea temperatures remain relatively cool, fluctuating from 7.8°C (46°F) to 15.7°C (60.3°F). March and April receive an average rainfall of 41mm (1.61") and 49mm (1.93") over 7 and 8 days, respectively, while May experiences nearly similar rainfall amounts but over 7 days.

During summer, Sveti Vlas boasts copious sunshine, longer daylight hours, and warmer sea temperatures. Average high and low temperatures progress from 24°C (75.2°F) and 15°C (59°F) in June towards 27°C (80.6°F) and 17°C (62.6°F) in July. Despite being the warmest, summer is also the driest season with the least rainfall, shown by reduced rainfall levels from 51mm (2.01") in June to 34mm (1.34") in August over 7 to 4 days.

Autumn indicates a downwards shift with temperatures in Sveti Vlas; average highs gradually reduce from 23°C (73.4°F) in September to 13°C (55.4°F) in November. Following a similar pattern, low temperatures diminish from 14°C (57.2°F) to 5°C (41°F). Further, the sea temperature drops from a comfortable 22.8°C (73°F) in September to a cooler 13.3°C (55.9°F) in November. Rainfall begins to peak again in autumn, attaining the highest point of 65mm (2.56") for the year in November.

Winter in Sveti Vlas is marked by chillier temperatures and shorter days. The temperatures dwell in the single digits with high temperatures spiraling down from 7°C (44.6°F) to 5°C (41°F) from December through January and low temperatures continue to fall below freezing point. In these colder months, the sea temperature averages between 13.3°C (55.9°F) and 8.1°C (46.6°F). Rainfall revolves around 60mm (2.36") to 49mm (1.93") and occurs over 8 to 7 days while the sunshine duration shrinks to its lowest yearly level of 2 to 3 hours daily.

Though Sveti Vlas, Bulgaria, is known in January for daily maximum temperatures reaching up to 5°C (41°F) while plunging to a chill-inducing -2°C (28.4°F) in the night, it offers various weather conditions, integral to its winter charm. Weather in January »

The weather slightly softens in February with a narrow increase in the daily temperature range, climbing up from January's colder clime. Sveti Vlas experiences a near-identical pattern of rainfall in February as the previous month, maintaining the typical winter ambience. Weather in February »

March sees welcoming modifications in the Sveti Vlas climate with daily high temperatures of 9°C (48.2°F) and lows of 2°C (35.6°F). Though it presents rainfall akin to the previous months, it hints at a shift towards lesser rainy days. Weather in March »

April in Sveti Vlas is marked by a jump in the thermometer with daily highs of 15°C (59°F), introducing the substantial warmth of the spring season. The features of rainfall remain consistent, adding an occasional touch of freshness to the increasingly warmer days. Weather in April »

Stepping into the threshold of summer, May in Sveti Vlas experiences a significant rise in temperatures. The rainfall scenario undergoes minor changes, gently fuelling the region's greenery. The sea transforms into a haven for early summer swimmers with a marked improvement in its temperature. Weather in May »

June ushers Sveti Vlas into the laps of summer with the temperature range climbing to agreeable highs of 24°C (75.2°F) and minimums of 15°C (59°F). The town sees a slight spike in its rain activity, contrasting interestingly with the warm atmosphere. Weather in June »

July stands as the most heated month in Sveti Vlas, witnessing temperature highs sizzling up to a maximum of 27°C (80.6°F) and a balmy low of 17°C (62.6°F). The rainfall records a drop, lending a dry characteristic to the summer month. Weather in July »

Though August experiences a slight dip in temperature from the previous month, it still delivers a warm atmosphere. Rainfall in Sveti Vlas decreases further, ensuring more clear skies and sunny days. The sea reaches its peak temperature, inviting holidaymakers for a pleasant swim. Weather in August »

September in Sveti Vlas welcomes the arrival of fall with decreasing temperatures. Rainfall curve shifts upwards, adding a distinctive touch to the season. The sea retains a considerable degree of its warmth, making beach visits enjoyable. Weather in September »

October further accentuates the characteristics of autumn weather. The cooling trend in Sveti Vlas continues with decreasing temperature levels. The rainfall shows an increase compared to the summer months, steeping the city in a moist autumnal glow. Weather in October »

November paints the picture of late autumn with further cooling temperatures. Rainfall in Sveti Vlas peaks, turning the surrounding landscape into an artist's canvas of vibrant colors. The sea turns progressively colder, reaching temperatures reminiscent of winter. Weather in November »

Finally, December escorts Sveti Vlas into the embrace of winter, with temperature maxima dipping to 7°C (44.6°F) and the night chill settling at around 1°C (33.8°F). The rainfall relaxes slightly from November's high but is still considerable, setting a wet winter scene. Weather in December »